<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		
	</head>
	<body>
		<button>111</button>
		<button>222</button>
		<button>333</button>
		<button>444</button>
		<button>555</button>
		<button>666</button>
		<button>777</button>
		<button>888</button>
		<button>999</button>
	
	</body>
	<script type="text/javascript">
		var btns=document.getElementsByTagName("button");
		for (let i=0;i<btns.length;i++) {
			btns[i].onclick=function(){
				console.log("you are clicking!!!"+event.target.innerHTML);
			}
			
			
		}
	</script>
</html>
